1. Field of the Invention
The present invention relates generally to sound equipment and, more specifically, to a low frequency generator comprising a housing having a recess extending therethrough and a diaphragm movable within the recess of the housing.
2. Description of the Prior Art
Numerous other sound generating devices designed for emitting a low frequency are present in the prior art. Typical of these are U.S. Pat. Nos. 2,069,242; 2,071,828; 2,517,727; 2,860,721; 4,164,988; 4,471,173; 4,628,154; 5,734,132; 5,825,901; and 5,930,373. While these sound generating devices may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described.
In an electro-acoustical energy converting system; a vibratory component, comprising an impulse responsive element; a flexing cylinder for mounting said element to permit piston-like vibration thereof and forming a fluid-tight junction therewith; a second component adapted for assembly with the first-named component, as a replaceable unit, and comprising adjustable means for supporting co-operating parts of said system; means for preliminarily coupling said components to permit adjustment and calibration of active elements at desired operating frequencies; and means to complete the coupling operation of the components in fluid-tight assembly with one another and without disturbing the adjustment.
In loud speakers and the like, the combination with a driving unit, of a driving diaphragm connected to be actuated by said unit, and a second diaphragm independently mounted in substantially parallel spaced relation to the first said diaphragm; the intervening space being in free communication with the atmosphere and of a width such that said second diaphragm is driven from the first solely by the acoustic vibration of the air in the space between said diaphragms.
A permanent magnet structure for a loudspeaker comprising a permanent magnet, a support therefore, a tip of magnetizable material but which is not a magnet, attached to the end of said magnet, a pole plate of magnetizable material carried by the support and enclosing at least portions of the magnet and pole tip, said pole tip having a thickness not less than half of that of the plate and not more than three quarters of that of the plate, said permanent magnet having anisotropic characteristics and said pole tip having isotropic characteristics, whereby the ratio of total useful flux to the volume of anisotropic material' is substantially a maximum.
A sound reproducing device comprising vibrating instrumentalities, a diaphragm operatively connected to said instrumentalities at its inner end and being unattached at its outer end, a support connected to said instrumentalities and spaced from said diaphragm, embodying an inwardly extending, attaching shelf at a point intermediate the outer and inner ends of said support, another shelf outwardly of said intermediate shelf and an outer rim outwardly of said other shelf, a gasket on said other shelf within said rim, and a flexible, expansible annular connector circumferentially attached to said diaphragm at a point intermediate the outer and inner ends thereof and attached to said attaching shelf, said diaphragm outer end being adjacent to and inwardly opposite said gasket and spaced therefrom.
A loudspeaker system is disclosed having a rigid framework which contains a high compliance loudspeaker connected to an adjustable air column tube. The adjustable air column tube provides exact ¼ wavelength tuning for the speaker system, to further improve its low frequency response, in accordance with tuned enclosure theory.
A planar diaphragm type magnetic transducer with an acoustically transparent magnetic backing, and a diaphragm overlying and spaced from the magnetic backing, the magnetic backing having magnetized strips lying parallel to each other and adjacent magnetized strips having opposite polarities at their faces confronting the diaphragm, the diaphragm being stiff and resisting flexing and connected by a flexible surround at its periphery.
An annular gap magnet system, in particular for a low frequency loudspeaker (Woofer), in which a coil is movable with a large stroke in the working air gap. A braking air gap provided in the region of the inner or lower pole plate produces a magnetic resistance in the pole plate so that a part of the magnetic flux flows over the braking air gap. This magnetic flux is opposed to the stray magnetic flux below the working air gap and excites a counter magnetic field which opposes further inward movement of the moving coil. In this way an impact of the moving coil against the inner or lower pole plate is prevented. In a low frequency loudspeaker the membrane carrying the moving coil may, therefore, be suspended extremely softly.
A concentric tube suspension system and loudspeaker system of the moving coil type, including a diaphragm supported by a frame, a voice coil including a former and voice coil winding supported by the former, and a suspension system for stabilizing and centering the voice coil in a magnetic gap while it is linearly displaced by an electromagnetic motor. The suspension system generally comprises a tubular stabilizer attached to the bottom surface of the diaphragm so as to concentrically straddle the voice coil and electromagnetic motor, and a lower corrugated suspension attached at one end to the frame and at the other end to the lower end of the stabilizer, wherein the stabilizer and lower suspension provide a centering force below the traditional neck joint location on the voice coil.
Apparatus (21) is described for reproducing low frequency sound in response to an applied electrical signal having a rotary acoustic radiator (22) comprised of a chamber (26) having a rotor assembly (58) including a shaft (61) and movable vanes (71, 72) secured to the shaft rotatably mounted in chamber for rotation on a longitudinal axis. Stationary vanes (62, 63) are mounted in the chamber and extend generally radially between the chamber walls and the shaft. The chamber has ports (64, 66, 67, 68) therein opening into the chamber and disposed adjacent the stationary vanes on opposite sides of said stationary vanes. The movable vanes are disposed on opposite sides of the stationary vanes and extend generally radially between the chamber walls and the shaft.
An apparatus for conveying to a listener a pseudo low frequency psycho-acoustic sensation (Pseudo-LFPS) of a sound signal, including: frequency unit capable of deriving from the sound signal high frequency signal and low frequency signal (LF signal) that extends over a low frequency range of interest. Harmonics generator coupled to the frequency generator and being capable of generating, for each fundamental frequency within the low frequency range of interest, a residue harmonic signal having a sequence of harmonics. The sequence of harmonics, generated with respect to each fundamental frequency contains a first group of harmonics that includes at least three consecutive harmonics from among a primary set of harmonics of the fundamental frequency. Loudness generator coupled to the harmonics generator and being capable of bringing the loudness of the residue harmonic signal to match the loudness of the low frequency signal. Summation unit capable of summing the residue harmonic signal and the high frequency signal so as to obtain psychoacoustic alternative signal.